Originally Posted by
dedwards0323
I also wouldn't use 5w50 oil even though it's on the recommended listing of oils for MB-229.3 spec (which applies to the Crossfire). I just don't operate the car at extreme operating conditions for any extended period of time to warrant using a multi-grade oil that is a little more stable in that operating environment. But like I stated, 5w50 is listed as an approved oil by M-B for meeting 229.3 spec and if someone wants to use that product, there doesn't seem to be any motor lubrication issue with using it.
You cannot use just any oil on that spec sheet, there are 5/30 and oils for diesels there and you would not use them. They would be like grass through a goose.
5/40 is OK, with a worn engine 5/50 would be OK as the wear would allow the thicker oil into the gap. So we can assume that PG's car is worn or soon will be worn using that oil.
